<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        *{
            background: #cccccc;
        }
        div{
            width: 100px;
            height: 100px;
            background: red !important;
        }
        .div1{
            text-align: center;
            line-height: 100px;
            margin: 0 auto;

            background: #2fff3d ;
        }
        #div1{
            font-size: 30px;
            color: white;

            /*background: #cccccc;*/
        }
    </style>
</head>
<body>


    <div class="div1" id="div1" >
        div
    </div>

</body>
</html>
